Spectral flow cytometry is transforming how CAR T-cell therapies are monitored throughout clinical development.

This peer-reviewed review article examines the expanding role of spectral flow cytometry in CAR T-cell clinical trials, highlighting its ability to support high-dimensional immune profiling, characterize cellular responses, and generate standardized data for biomarker research and regulatory submissions.

Key topics include:

• The advantages of spectral flow cytometry for high-parameter immune profiling in CAR T-cell clinical trials
• Strategies for monitoring CAR T-cell distribution, expansion, persistence, and exhaustion following infusion
• Deep immunophenotyping approaches to characterize memory, activation, and inhibitory cell states associated with therapeutic response
• Methods for identifying and quantifying CAR T-cells and target antigen expression using flow cytometry
• Best practices for assay validation, standardization, cross-instrument comparability, and rare event detection aligned with CLSI H62 guidance
• The use of flow cytometry to assess measurable residual disease (MRD), endogenous immune populations, and anti-drug antibody (ADA) responses to CAR T-cell therapies

As CAR T-cell therapies continue to expand beyond hematologic malignancies into solid tumors and autoimmune diseases, spectral flow cytometry is emerging as a foundational technology for generating the high-quality, reproducible data needed to accelerate cellular therapy development and improve patient outcomes.